/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/

/*****************************************************************************
* fsm.c - Network Control Protocol Finite State Machine program file.
*
* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
* portions Copyright (c) 1997 by Global Election Systems Inc.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
* REVISION HISTORY
*
* 03-01-01 Marc Boucher <marc@mbsi.ca>
*   Ported to lwIP.
* 97-12-01 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
*   Original based on BSD fsm.c.
*****************************************************************************/
/*
 * fsm.c - {Link, IP} Control Protocol Finite State Machine.
 *
 * Copyright (c) 1989 Carnegie Mellon University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Carnegie Mellon University.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/*
 * TODO:
 * Randomize fsm id on link/init.
 * Deal with variable outgoing MTU.
 */

#include "lwip/opt.h"

#if PPP_SUPPORT					/* don't build if not configured for use in lwipopts.h */

#include "ppp_impl.h"
#include "pppdebug.h"

#include "fsm.h"

#include <string.h>

#if PPP_DEBUG
static const char *ppperr_strerr[] = {
	"LS_INITIAL",				/* LS_INITIAL  0 */
	"LS_STARTING",				/* LS_STARTING 1 */
	"LS_CLOSED",				/* LS_CLOSED   2 */
	"LS_STOPPED",				/* LS_STOPPED  3 */
	"LS_CLOSING",				/* LS_CLOSING  4 */
	"LS_STOPPING",				/* LS_STOPPING 5 */
	"LS_REQSENT",				/* LS_REQSENT  6 */
	"LS_ACKRCVD",				/* LS_ACKRCVD  7 */
	"LS_ACKSENT",				/* LS_ACKSENT  8 */
	"LS_OPENED"					/* LS_OPENED   9 */
};
#endif							/* PPP_DEBUG */

static void fsm_timeout(void *);
static void fsm_rconfreq(fsm *, u_char, u_char *, int);
static void fsm_rconfack(fsm *, int, u_char *, int);
static void fsm_rconfnakrej(fsm *, int, int, u_char *, int);
static void fsm_rtermreq(fsm *, int, u_char *, int);
static void fsm_rtermack(fsm *);
static void fsm_rcoderej(fsm *, u_char *, int);
static void fsm_sconfreq(fsm *, int);

#define PROTO_NAME(f) ((f)->callbacks->proto_name)

int peer_mru[NUM_PPP];

/*
 * fsm_init - Initialize fsm.
 *
 * Initialize fsm state.
 */
void fsm_init(fsm *f)
{
	f->state = LS_INITIAL;
	f->flags = 0;
	f->id = 0;					/* XXX Start with random id? */
	f->timeouttime = FSM_DEFTIMEOUT;
	f->maxconfreqtransmits = FSM_DEFMAXCONFREQS;
	f->maxtermtransmits = FSM_DEFMAXTERMREQS;
	f->maxnakloops = FSM_DEFMAXNAKLOOPS;
	f->term_reason_len = 0;
}

/*
 * fsm_lowerup - The lower layer is up.
 */
void fsm_lowerup(fsm *f)
{
	int oldState = f->state;

	LWIP_UNUSED_ARG(oldState);

	switch (f->state) {
	case LS_INITIAL:
		f->state = LS_CLOSED;
		break;

	case LS_STARTING:
		if (f->flags & OPT_SILENT) {
			f->state = LS_STOPPED;
		} else {
			/* Send an initial configure-request */
			fsm_sconfreq(f, 0);
			f->state = LS_REQSENT;
		}
		break;

	default:
		FSMDEBUG(LOG_INFO, ("%s: Up event in state %d (%s)!\n", PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
	}

	FSMDEBUG(LOG_INFO, ("%s: lowerup state %d (%s) -> %d (%s)\n", PROTO_NAME(f), oldState, ppperr_strerr[oldState], f->state, ppperr_strerr[f->state]));
}

/*
 * fsm_lowerdown - The lower layer is down.
 *
 * Cancel all timeouts and inform upper layers.
 */
void fsm_lowerdown(fsm *f)
{
	int oldState = f->state;

	LWIP_UNUSED_ARG(oldState);

	switch (f->state) {
	case LS_CLOSED:
		f->state = LS_INITIAL;
		break;

	case LS_STOPPED:
		f->state = LS_STARTING;
		if (f->callbacks->starting) {
			(*f->callbacks->starting)(f);
		}
		break;

	case LS_CLOSING:
		f->state = LS_INITIAL;
		UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
		break;

	case LS_STOPPING:
	case LS_REQSENT:
	case LS_ACKRCVD:
	case LS_ACKSENT:
		f->state = LS_STARTING;
		UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
		break;

	case LS_OPENED:
		if (f->callbacks->down) {
			(*f->callbacks->down)(f);
		}
		f->state = LS_STARTING;
		break;

	default:
		FSMDEBUG(LOG_INFO, ("%s: Down event in state %d (%s)!\n", PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
	}

	FSMDEBUG(LOG_INFO, ("%s: lowerdown state %d (%s) -> %d (%s)\n", PROTO_NAME(f), oldState, ppperr_strerr[oldState], f->state, ppperr_strerr[f->state]));
}

/*
 * fsm_open - Link is allowed to come up.
 */
void fsm_open(fsm *f)
{
	int oldState = f->state;

	LWIP_UNUSED_ARG(oldState);

	switch (f->state) {
	case LS_INITIAL:
		f->state = LS_STARTING;
		if (f->callbacks->starting) {
			(*f->callbacks->starting)(f);
		}
		break;

	case LS_CLOSED:
		if (f->flags & OPT_SILENT) {
			f->state = LS_STOPPED;
		} else {
			/* Send an initial configure-request */
			fsm_sconfreq(f, 0);
			f->state = LS_REQSENT;
		}
		break;

	case LS_CLOSING:
		f->state = LS_STOPPING;
	/* fall through */
	case LS_STOPPED:
	case LS_OPENED:
		if (f->flags & OPT_RESTART) {
			fsm_lowerdown(f);
			fsm_lowerup(f);
		}
		break;
	}

	FSMDEBUG(LOG_INFO, ("%s: open state %d (%s) -> %d (%s)\n", PROTO_NAME(f), oldState, ppperr_strerr[oldState], f->state, ppperr_strerr[f->state]));
}

#if 0							/* backport pppd 2.4.4b1; */
/*
 * terminate_layer - Start process of shutting down the FSM
 *
 * Cancel any timeout running, notify upper layers we're done, and
 * send a terminate-request message as configured.
 */
static void terminate_layer(fsm *f, int nextstate)
{
	/* @todo */
}
#endif

/*
 * fsm_close - Start closing connection.
 *
 * Cancel timeouts and either initiate close or possibly go directly to
 * the LS_CLOSED state.
 */
void fsm_close(fsm *f, char *reason)
{
	int oldState = f->state;

	LWIP_UNUSED_ARG(oldState);

	f->term_reason = reason;
	f->term_reason_len = (reason == NULL ? 0 : (int)strlen(reason));
	switch (f->state) {
	case LS_STARTING:
		f->state = LS_INITIAL;
		break;
	case LS_STOPPED:
		f->state = LS_CLOSED;
		break;
	case LS_STOPPING:
		f->state = LS_CLOSING;
		break;

	case LS_REQSENT:
	case LS_ACKRCVD:
	case LS_ACKSENT:
	case LS_OPENED:
		if (f->state != LS_OPENED) {
			UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
		} else if (f->callbacks->down) {
			(*f->callbacks->down)(f);	/* Inform upper layers we're down */
		}
		/* Init restart counter, send Terminate-Request */
		f->retransmits = f->maxtermtransmits;
		fsm_sdata(f, TERMREQ, f->reqid = ++f->id, (u_char *) f->term_reason, f->term_reason_len);
		TIMEOUT(fsm_timeout, f, f->timeouttime);
		--f->retransmits;

		f->state = LS_CLOSING;
		break;
	}

	FSMDEBUG(LOG_INFO, ("%s: close reason=%s state %d (%s) -> %d (%s)\n", PROTO_NAME(f), reason, oldState, ppperr_strerr[oldState], f->state, ppperr_strerr[f->state]));
}

/*
 * fsm_timeout - Timeout expired.
 */
static void fsm_timeout(void *arg)
{
	fsm *f = (fsm *) arg;

	switch (f->state) {
	case LS_CLOSING:
	case LS_STOPPING:
		if (f->retransmits <= 0) {
			FSMDEBUG(LOG_WARNING, ("%s: timeout sending Terminate-Request state=%d (%s)\n", PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
			/*
			 * We've waited for an ack long enough.  Peer probably heard us.
			 */
			f->state = (f->state == LS_CLOSING) ? LS_CLOSED : LS_STOPPED;
			if (f->callbacks->finished) {
				(*f->callbacks->finished)(f);
			}
		} else {
			FSMDEBUG(LOG_WARNING, ("%s: timeout resending Terminate-Requests state=%d (%s)\n", PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
			/* Send Terminate-Request */
			fsm_sdata(f, TERMREQ, f->reqid = ++f->id, (u_char *) f->term_reason, f->term_reason_len);
			TIMEOUT(fsm_timeout, f, f->timeouttime);
			--f->retransmits;
		}
		break;

	case LS_REQSENT:
	case LS_ACKRCVD:
	case LS_ACKSENT:
		if (f->retransmits <= 0) {
			FSMDEBUG(LOG_WARNING, ("%s: timeout sending Config-Requests state=%d (%s)\n", PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
			f->state = LS_STOPPED;
			if ((f->flags & OPT_PASSIVE) == 0 && f->callbacks->finished) {
				(*f->callbacks->finished)(f);
			}
		} else {
			FSMDEBUG(LOG_WARNING, ("%s: timeout resending Config-Request state=%d (%s)\n", PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
			/* Retransmit the configure-request */
			if (f->callbacks->retransmit) {
				(*f->callbacks->retransmit)(f);
			}
			fsm_sconfreq(f, 1);	/* Re-send Configure-Request */
			if (f->state == LS_ACKRCVD) {
				f->state = LS_REQSENT;
			}
		}
		break;

	default:
		FSMDEBUG(LOG_INFO, ("%s: UNHANDLED timeout event in state %d (%s)!\n", PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
	}
}

/*
 * fsm_input - Input packet.
 */
void fsm_input(fsm *f, u_char *inpacket, int l)
{
	u_char *inp = inpacket;
	u_char code, id;
	int len;

	/*
	 * Parse header (code, id and length).
	 * If packet too short, drop it.
	 */
	if (l < HEADERLEN) {
		FSMDEBUG(LOG_WARNING, ("fsm_input(%x): Rcvd short header.\n", f->protocol));
		return;
	}
	GETCHAR(code, inp);
	GETCHAR(id, inp);
	GETSHORT(len, inp);
	if (len < HEADERLEN) {
		FSMDEBUG(LOG_INFO, ("fsm_input(%x): Rcvd illegal length.\n", f->protocol));
		return;
	}
	if (len > l) {
		FSMDEBUG(LOG_INFO, ("fsm_input(%x): Rcvd short packet.\n", f->protocol));
		return;
	}
	len -= HEADERLEN;			/* subtract header length */

	if (f->state == LS_INITIAL || f->state == LS_STARTING) {
		FSMDEBUG(LOG_INFO, ("fsm_input(%x): Rcvd packet in state %d (%s).\n", f->protocol, f->state, ppperr_strerr[f->state]));
		return;
	}
	FSMDEBUG(LOG_INFO, ("fsm_input(%s):%d,%d,%d\n", PROTO_NAME(f), code, id, l));
	/*
	 * Action depends on code.
	 */
	switch (code) {
	case CONFREQ:
		fsm_rconfreq(f, id, inp, len);
		break;

	case CONFACK:
		fsm_rconfack(f, id, inp, len);
		break;

	case CONFNAK:
	case CONFREJ:
		fsm_rconfnakrej(f, code, id, inp, len);
		break;

	case TERMREQ:
		fsm_rtermreq(f, id, inp, len);
		break;

	case TERMACK:
		fsm_rtermack(f);
		break;

	case CODEREJ:
		fsm_rcoderej(f, inp, len);
		break;

	default:
		FSMDEBUG(LOG_INFO, ("fsm_input(%s): default: \n", PROTO_NAME(f)));
		if (!f->callbacks->extcode || !(*f->callbacks->extcode)(f, code, id, inp, len)) {
			fsm_sdata(f, CODEREJ, ++f->id, inpacket, len + HEADERLEN);
		}
		break;
	}
}

/*
 * fsm_rconfreq - Receive Configure-Request.
 */
static void fsm_rconfreq(fsm *f, u_char id, u_char *inp, int len)
{
	int code, reject_if_disagree;

	FSMDEBUG(LOG_INFO, ("fsm_rconfreq(%s): Rcvd id %d state=%d (%s)\n", PROTO_NAME(f), id, f->state, ppperr_strerr[f->state]));
	switch (f->state) {
	case LS_CLOSED:
		/* Go away, we're closed */
		fsm_sdata(f, TERMACK, id, NULL, 0);
		return;
	case LS_CLOSING:
	case LS_STOPPING:
		return;

	case LS_OPENED:
		/* Go down and restart negotiation */
		if (f->callbacks->down) {
			(*f->callbacks->down)(f);	/* Inform upper layers */
		}
		fsm_sconfreq(f, 0);		/* Send initial Configure-Request */
		break;

	case LS_STOPPED:
		/* Negotiation started by our peer */
		fsm_sconfreq(f, 0);		/* Send initial Configure-Request */
		f->state = LS_REQSENT;
		break;
	}

	/*
	 * Pass the requested configuration options
	 * to protocol-specific code for checking.
	 */
	if (f->callbacks->reqci) {	/* Check CI */
		reject_if_disagree = (f->nakloops >= f->maxnakloops);
		code = (*f->callbacks->reqci)(f, inp, &len, reject_if_disagree);
	} else if (len) {
		code = CONFREJ;			/* Reject all CI */
	} else {
		code = CONFACK;
	}

	/* send the Ack, Nak or Rej to the peer */
	fsm_sdata(f, (u_char) code, id, inp, len);

	if (code == CONFACK) {
		if (f->state == LS_ACKRCVD) {
			UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
			f->state = LS_OPENED;
			if (f->callbacks->up) {
				(*f->callbacks->up)(f);	/* Inform upper layers */
			}
		} else {
			f->state = LS_ACKSENT;
		}
		f->nakloops = 0;
	} else {
		/* we sent CONFACK or CONFREJ */
		if (f->state != LS_ACKRCVD) {
			f->state = LS_REQSENT;
		}
		if (code == CONFNAK) {
			++f->nakloops;
		}
	}
}

/*
 * fsm_rconfack - Receive Configure-Ack.
 */
static void fsm_rconfack(fsm *f, int id, u_char *inp, int len)
{
	FSMDEBUG(LOG_INFO, ("fsm_rconfack(%s): Rcvd id %d state=%d (%s)\n", PROTO_NAME(f), id, f->state, ppperr_strerr[f->state]));

	if (id != f->reqid || f->seen_ack) {	/* Expected id? */
		return;					/* Nope, toss... */
	}
	if (!(f->callbacks->ackci ? (*f->callbacks->ackci)(f, inp, len) : (len == 0))) {
		/* Ack is bad - ignore it */
		FSMDEBUG(LOG_INFO, ("%s: received bad Ack (length %d)\n", PROTO_NAME(f), len));
		return;
	}
	f->seen_ack = 1;

	switch (f->state) {
	case LS_CLOSED:
	case LS_STOPPED:
		fsm_sdata(f, TERMACK, (u_char) id, NULL, 0);
		break;

	case LS_REQSENT:
		f->state = LS_ACKRCVD;
		f->retransmits = f->maxconfreqtransmits;
		break;

	case LS_ACKRCVD:
		/* Huh? an extra valid Ack? oh well... */
		UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
		fsm_sconfreq(f, 0);
		f->state = LS_REQSENT;
		break;

	case LS_ACKSENT:
		UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
		f->state = LS_OPENED;
		f->retransmits = f->maxconfreqtransmits;
		if (f->callbacks->up) {
			(*f->callbacks->up)(f);	/* Inform upper layers */
		}
		break;

	case LS_OPENED:
		/* Go down and restart negotiation */
		if (f->callbacks->down) {
			(*f->callbacks->down)(f);	/* Inform upper layers */
		}
		fsm_sconfreq(f, 0);		/* Send initial Configure-Request */
		f->state = LS_REQSENT;
		break;
	}
}

/*
 * fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
 */
static void fsm_rconfnakrej(fsm *f, int code, int id, u_char *inp, int len)
{
	int (*proc)(fsm *, u_char *, int);
	int ret;

	FSMDEBUG(LOG_INFO, ("fsm_rconfnakrej(%s): Rcvd id %d state=%d (%s)\n", PROTO_NAME(f), id, f->state, ppperr_strerr[f->state]));

	if (id != f->reqid || f->seen_ack) {	/* Expected id? */
		return;					/* Nope, toss... */
	}
	proc = (code == CONFNAK) ? f->callbacks->nakci : f->callbacks->rejci;
	if (!proc || !((ret = proc(f, inp, len)))) {
		/* Nak/reject is bad - ignore it */
		FSMDEBUG(LOG_INFO, ("%s: received bad %s (length %d)\n", PROTO_NAME(f), (code == CONFNAK ? "Nak" : "reject"), len));
		return;
	}
	f->seen_ack = 1;

	switch (f->state) {
	case LS_CLOSED:
	case LS_STOPPED:
		fsm_sdata(f, TERMACK, (u_char) id, NULL, 0);
		break;

	case LS_REQSENT:
	case LS_ACKSENT:
		/* They didn't agree to what we wanted - try another request */
		UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
		if (ret < 0) {
			f->state = LS_STOPPED;	/* kludge for stopping CCP */
		} else {
			fsm_sconfreq(f, 0);	/* Send Configure-Request */
		}
		break;

	case LS_ACKRCVD:
		/* Got a Nak/reject when we had already had an Ack?? oh well... */
		UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
		fsm_sconfreq(f, 0);
		f->state = LS_REQSENT;
		break;

	case LS_OPENED:
		/* Go down and restart negotiation */
		if (f->callbacks->down) {
			(*f->callbacks->down)(f);	/* Inform upper layers */
		}
		fsm_sconfreq(f, 0);		/* Send initial Configure-Request */
		f->state = LS_REQSENT;
		break;
	}
}

/*
 * fsm_rtermreq - Receive Terminate-Req.
 */
static void fsm_rtermreq(fsm *f, int id, u_char *p, int len)
{
	LWIP_UNUSED_ARG(p);

	FSMDEBUG(LOG_INFO, ("fsm_rtermreq(%s): Rcvd id %d state=%d (%s)\n", PROTO_NAME(f), id, f->state, ppperr_strerr[f->state]));

	switch (f->state) {
	case LS_ACKRCVD:
	case LS_ACKSENT:
		f->state = LS_REQSENT;	/* Start over but keep trying */
		break;

	case LS_OPENED:
		if (len > 0) {
			FSMDEBUG(LOG_INFO, ("%s terminated by peer (%p)\n", PROTO_NAME(f), p));
		} else {
			FSMDEBUG(LOG_INFO, ("%s terminated by peer\n", PROTO_NAME(f)));
		}
		if (f->callbacks->down) {
			(*f->callbacks->down)(f);	/* Inform upper layers */
		}
		f->retransmits = 0;
		f->state = LS_STOPPING;
		TIMEOUT(fsm_timeout, f, f->timeouttime);
		break;
	}

	fsm_sdata(f, TERMACK, (u_char) id, NULL, 0);
}

/*
 * fsm_rtermack - Receive Terminate-Ack.
 */
static void fsm_rtermack(fsm *f)
{
	FSMDEBUG(LOG_INFO, ("fsm_rtermack(%s): state=%d (%s)\n", PROTO_NAME(f), f->state, ppperr_strerr[f->state]));

	switch (f->state) {
	case LS_CLOSING:
		UNTIMEOUT(fsm_timeout, f);
		f->state = LS_CLOSED;
		if (f->callbacks->finished) {
			(*f->callbacks->finished)(f);
		}
		break;

	case LS_STOPPING:
		UNTIMEOUT(fsm_timeout, f);
		f->state = LS_STOPPED;
		if (f->callbacks->finished) {
			(*f->callbacks->finished)(f);
		}
		break;

	case LS_ACKRCVD:
		f->state = LS_REQSENT;
		break;

	case LS_OPENED:
		if (f->callbacks->down) {
			(*f->callbacks->down)(f);	/* Inform upper layers */
		}
		fsm_sconfreq(f, 0);
		break;
	default:
		FSMDEBUG(LOG_INFO, ("fsm_rtermack(%s): UNHANDLED state=%d (%s)!!!\n", PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
	}
}

/*
 * fsm_rcoderej - Receive an Code-Reject.
 */
static void fsm_rcoderej(fsm *f, u_char *inp, int len)
{
	u_char code, id;

	FSMDEBUG(LOG_INFO, ("fsm_rcoderej(%s): state=%d (%s)\n", PROTO_NAME(f), f->state, ppperr_strerr[f->state]));

	if (len < HEADERLEN) {
		FSMDEBUG(LOG_INFO, ("fsm_rcoderej: Rcvd short Code-Reject packet!\n"));
		return;
	}
	GETCHAR(code, inp);
	GETCHAR(id, inp);
	FSMDEBUG(LOG_WARNING, ("%s: Rcvd Code-Reject for code %d, id %d\n", PROTO_NAME(f), code, id));

	if (f->state == LS_ACKRCVD) {
		f->state = LS_REQSENT;
	}
}

/*
 * fsm_protreject - Peer doesn't speak this protocol.
 *
 * Treat this as a catastrophic error (RXJ-).
 */
void fsm_protreject(fsm *f)
{
	switch (f->state) {
	case LS_CLOSING:
		UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
	/* fall through */
	case LS_CLOSED:
		f->state = LS_CLOSED;
		if (f->callbacks->finished) {
			(*f->callbacks->finished)(f);
		}
		break;

	case LS_STOPPING:
	case LS_REQSENT:
	case LS_ACKRCVD:
	case LS_ACKSENT:
		UNTIMEOUT(fsm_timeout, f);	/* Cancel timeout */
	/* fall through */
	case LS_STOPPED:
		f->state = LS_STOPPED;
		if (f->callbacks->finished) {
			(*f->callbacks->finished)(f);
		}
		break;

	case LS_OPENED:
		if (f->callbacks->down) {
			(*f->callbacks->down)(f);
		}
		/* Init restart counter, send Terminate-Request */
		f->retransmits = f->maxtermtransmits;
		fsm_sdata(f, TERMREQ, f->reqid = ++f->id, (u_char *) f->term_reason, f->term_reason_len);
		TIMEOUT(fsm_timeout, f, f->timeouttime);
		--f->retransmits;

		f->state = LS_STOPPING;
		break;

	default:
		FSMDEBUG(LOG_INFO, ("%s: Protocol-reject event in state %d (%s)!\n", PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
	}
}

/*
 * fsm_sconfreq - Send a Configure-Request.
 */
static void fsm_sconfreq(fsm *f, int retransmit)
{
	u_char *outp;
	int cilen;

	if (f->state != LS_REQSENT && f->state != LS_ACKRCVD && f->state != LS_ACKSENT) {
		/* Not currently negotiating - reset options */
		if (f->callbacks->resetci) {
			(*f->callbacks->resetci)(f);
		}
		f->nakloops = 0;
	}

	if (!retransmit) {
		/* New request - reset retransmission counter, use new ID */
		f->retransmits = f->maxconfreqtransmits;
		f->reqid = ++f->id;
	}

	f->seen_ack = 0;

	/*
	 * Make up the request packet
	 */
	outp = outpacket_buf[f->unit] + PPP_HDRLEN + HEADERLEN;
	if (f->callbacks->cilen && f->callbacks->addci) {
		cilen = (*f->callbacks->cilen)(f);
		if (cilen > peer_mru[f->unit] - (int)HEADERLEN) {
			cilen = peer_mru[f->unit] - HEADERLEN;
		}
		if (f->callbacks->addci) {
			(*f->callbacks->addci)(f, outp, &cilen);
		}
	} else {
		cilen = 0;
	}

	/* send the request to our peer */
	fsm_sdata(f, CONFREQ, f->reqid, outp, cilen);

	/* start the retransmit timer */
	--f->retransmits;
	TIMEOUT(fsm_timeout, f, f->timeouttime);

	FSMDEBUG(LOG_INFO, ("%s: sending Configure-Request, id %d\n", PROTO_NAME(f), f->reqid));
}

/*
 * fsm_sdata - Send some data.
 *
 * Used for all packets sent to our peer by this module.
 */
void fsm_sdata(fsm *f, u_char code, u_char id, u_char *data, int datalen)
{
	u_char *outp;
	int outlen;

	/* Adjust length to be smaller than MTU */
	outp = outpacket_buf[f->unit];
	if (datalen > peer_mru[f->unit] - (int)HEADERLEN) {
		datalen = peer_mru[f->unit] - HEADERLEN;
	}
	if (datalen && data != outp + PPP_HDRLEN + HEADERLEN) {
		BCOPY(data, outp + PPP_HDRLEN + HEADERLEN, datalen);
	}
	outlen = datalen + HEADERLEN;
	MAKEHEADER(outp, f->protocol);
	PUTCHAR(code, outp);
	PUTCHAR(id, outp);
	PUTSHORT(outlen, outp);
	pppWrite(f->unit, outpacket_buf[f->unit], outlen + PPP_HDRLEN);
	FSMDEBUG(LOG_INFO, ("fsm_sdata(%s): Sent code %d,%d,%d.\n", PROTO_NAME(f), code, id, outlen));
}

#endif							/* PPP_SUPPORT */
